Electronic video dental camera

ABSTRACT

An electronic video dental camera is provided which overcomes the disadvantages of both prior art dental mirrors, endoscopes, and video endoscopes. The electronic video dental camera is readily manipulated by dentists who are familiar with the manipulation of dental mirrors. Such an electronic video dental camera includes a handle to be held the user, and a camera head located at the distal end of the handle, with the camera head being formed at an angle to the handle, as in prior art dental mirrors. One embodiment includes provision for the flow of a selected fluid in order to defog and/or clean the camera lens. In one embodiment, the camera head includes light sources for illuminating the area to be viewed. In one embodiment, the handle of the dental camera includes means for transporting all appropriate signals and fluids to and from the camera head, and, if desired, valves and switching means located on the handle for controlling such communication to the camera head. One embodiment includes a dental camera head which allows a number of attachments to be used, such as a telephoto lens, wide angle lens, relay lens, and transillumination devices. In an alternative embodiment, the dental camera is attached to another dental instrument, such as a dentist&#39;s drill, thereby allowing video monitoring of the task being performed. In another embodiment, the dental camera is formed as an integral part of the dental instrument.

This application is a divisional of U.S. Ser. No. 07/817,923, filed Jan.6, 1992, (now U.S. Pat. No. 5,290,168), which is a divisional of07/388,666, filed Aug. 2, 1989 (now U.S. Pat. No. 5,115,307), which inturn is a divisional of U.S. Ser. No. 07/149,521, filed Jan. 8, 1988,(now U.S. Pat. No. 5,016,098) which is a continuation-in-partapplication of U.S. Ser. No. 022,171, filed Mar. 5, 1987 (now U.S. Pat.No. 4,727,416).

BACKGROUND OF THE INVENTION

This invention is an electronic video dental camera having a handle andbeau for use in placement in a dental patient's mouth, and allowingareas within the mouth be displayed via a video signal.

For years, dentists have used dental mirrors for insertion in a dentalpatients' mouth for reflecting images of areas within the patients'mouth for viewing by the dentist. This technique works, although it hasseveral disadvantages. First, it is often difficult to hold the dentalmirror in an appropriate position in order to reflect the desired image.Secondly, it is more difficult to ensure that proper lighting isavailable to the area within the mouth to be reflected by the dentalmirror. An even greater disadvantage is that it is very difficult to usesuch prior art dental mirrors in a situation where a dentist wishes todiscuss certain regions within the mouth with other people, be it thepatient, colleagues, dental assistants, or students in a teachinginstitution.

Electronic video endoscopes have been used in recent years, for exampleas is described in U.S. patent application Ser. No. 611,684 filed May18, 1984 on an invention of Cooper et al, which is hereby incorporatedby reference. Such prior art video endoscopes use either fiber optics ora miniature camera, such as a charge coupled device (CCD), in order totransport an image to a monitor. Such prior art video endoscopes come ina variety of sizes, but are typically rather small and tubular in naturein order that they maybe easily inserted within a body cavity orsurgical opening. Certain prior art endoscopes include a light sourcelocated at their end in order to ensure proper lighting is available forillumination of the area of the desired image.

However, such prior art video endoscopes were not specifically designedfor use in dental applications and are rather clumsy in suchapplications. As one example, it is very difficult, if not impossible,to properly view the lingual aspects of the teeth using such prior artvideo endoscopes, due to their tubular shape.

SUMMARY OF THE INVENTION

In accordance with the teachings of this invention, an electronic videodental camera is provided which overcomes the disadvantages of bothprior art dental mirrors, endoscopes, and video endoscopes. Inaccordance with the teachings of this invention, an electronic videodental camera is provided having a general shape of prior art dentalmirrors, thereby being readily manipulated by dentists who areuniversally familiar with the manipulation of prior art dental mirrors.Such an electronic video dental camera includes a handle to be held theuser, and a camera head located at the distal end of the handle, withthe camera head being formed at an angle to the handle, as in prior artdental mirrors. In one embodiment, means are provided to cause, asdesired, the flow of a selected fluid over the camera lens in order todefog and/or clean the camera lens thereby allowing proper viewing. Inone embodiment, the camera head also includes light sources for properlyilluminating the area to be viewed. As a feature of one embodiment ofthis invention, the handle of the dental camera includes means fortransporting all appropriate signals and fluids to and from the camerahead, and, if desired, valves and switching means located on the handlefor controlling such communication to the camera head.

In one embodiment of this invention, the handle is uniquely designed toinclude electronics, such as video amplifiers and imaging device drivercircuitry, thereby eliminating the need to include this circuitry in thecamera head itself. In an alternative embodiment of this invention,elements of this electronic circuitry is located in the cable, orconnectors, or in the video processor unit itself.

One embodiment includes a dental camera head which allows a number ofattachments to be used, such as a telephoto lens, wide angle lens, relaylens, and transillumination devices. In an alternative embodiment ofthis invention, the dental camera is attached to another dentalinstrument, such as a dentist's drill, thereby allowing video monitoringof the task being performed by the dentist. In yet another embodiment ofthis invention, the dental camera is formed as an integral part of thedental instrument, such as a dental drill.

BRIEF DESCRIPTION OF THE DRAWINGS

FIG. 1 is a diagram depicting the use of an electronic video dentalcamera system constructed in accordance with the teachings of thisinvention;

FIG. 2 is a cross sectional view of one embodiment of a video dentalcamera constructed in accordance with the teachings of this invention;

FIG. 3 is a plan view of one embodiment of a camera head constructed inaccordance with the teachings of this invention;

FIG. 4 is a cross sectional view of one embodiment of a camera headconstructed in accordance with the teachings of this invention;

FIG. 5 is a block diagram depicting a dental camera system constructedin accordance with the teachings of this invention;

FIG. 6 is a diagram depicting a dental camera constructed in accordancewith the teachings of this invention depicting where certain electronicsmay be conveniently located;

FIG. 7 depicts one embodiment of a dental camera constructed inaccordance with the teachings of this invention which includes a dentalcamera head designed for receiving one of a plurality of attachments,such as the wide angle lens shown in FIG. 7;

FIGS. 7a, 7b and 7c and 7d depict a telephoto lens, a relay lens, and analternative embodiment of a relay lens, respectively, suitable for usewith the dental camera head of FIG. 7;

FIG. 8 is an alternative embodiment of a dental camera head constructedin accordance with the teachings of this invention which allows one of aplurality of attachments to be used, and a wide angle lens serving assuch an attachment;

FIGS. 8a and 8b depict a telephoto lens, and a relay lens, respectively,suitable for use with the camera head of FIG. 8;

FIGS. 9a through 9f depict various embodiments of a transilluminationdevice constructed in accordance with the teachings of this invention;

FIG. 10 depicts one embodiment of a dental camera constructed inaccordance with the teachings of this invention and which is attached toa dental instrument;

FIG. 11 is an alternative embodiment of a dental camera attached to adental instrument; and

FIG. 12 is a view of one embodiment of a dental camera constructed inaccordance with the teachings of this invention which is integrallyformed with a dental instrument.

DETAILED DESCRIPTION OF THE INVENTION

FIG. 1 shows the use of a dental camera 10 constructed in accordancewith the teachings of this invention. Video processor and control means8 serves to provide power, light and, if desired, fluid and otherappropriate signals via cable 7 to dental camera 10. Video processor andcontrol means 8 provides a video signal to video monitor 6 in order thatusers may view a location within a patient's mouth by way of dentalcamera 10. If desired, foot switch 9 is used to provide a signal tovideo processor and control means 8 indicating when air and/or fluidsare to be sent by video processor and control means 8 to dental camera10.

FIG. 2 shows a cross section of one embodiment of a video dental cameraconstructed in accordance with the teachings of this invention. Videodental camera 10 includes body 16 having handle 11 suitable for beingheld by an operator, and, if desired having forward extension 13. At oneend of handle 11 is located connector 12 for connection, via a cableassembly (not shown) to video processor and control unit 8 (FIG. 1). Ifdesired, forward extension 13 and handle 11 have generally circularcross section, although suitable shapes, such as octagonol, andpolygonal can be used. The important point is that handle 11 should beeasily and comfortably griped by the user, and forward extension 13should be of a general size and cross section which is convenient forinsertion into the patient's mouth and, of course, comfortable for thepatient.

Located at the distal end of forward extension 13, and mounted onforward extension 13 at an angle A to forward extension 13, is camerahead 14. Face 15 of camera head 14 includes means for receiving an imagewithin a patient's mouth to be displayed on a video monitor. In oneembodiment of this invention, such means for receiving the image isfiber optic tubes or one or more rod lens assemblies or a combinationthereof with or without additional lenses, which transmit the image toan image sensor (not shown) either within forward extension 13, body 16or, in another embodiment of this invention, the image is transmitted byone or more rod lens assemblies or fiber optic cable, or a combinationthereof with or without additional lenses, through connector 12 to animage sensor located in external video equipment (not shown). However,in a preferred embodiment the image sensor is located directly in camerahead 14 and receives the image from the patient's mouth via a lens,without the need for fiber optics.

FIG. 3 shows a cross sectional phantom view of camera head 14. In thisembodiment, fiber optic light guides 30a and 30b are used to receivelight from a light source (not shown ) which may comprise, for example ahalogen lamp or a Xenon are lamp located at the proximal end of lightguides 30a and 3Ob, and conduct this light through fiber opticcurvatures 31a and 31b to illumination lenses 32a and 32b respectively.Also shown in FIG. 3 is image lens 33 and image sensor 35 which ismounted on hybrid assembly substrate 36 located within cavity 37. Asshown in FIG. 3, in one embodiment of this invention, the center of theends of fiber optic light pipes 30a and 30b are offset from the centerof illumination lenses 32a and 32b, respectively, in a direction towardimage lens 33. This causes the light being emitted from fiber opticlight pipes 30a and 30b to be directed toward the image being viewed.Also, in one embodiment of this invention, illumination lenses 32a and32b are dispersion lenses which include a "frosting" to disperse thelight image sensor 35 is connected to video control cable 34 whichcommunicates power and control signals to image sensor 35 andcommunicates video signals to the video processor and control means 8 ofFIG. 1. As an alternative embodiment, a third fiber optic cable or a rodlens assembly (not shown) is used to conduct the image from image lens33 to an image sensor located in forward extension 13, handle 11, or viaconnector 12 (FIG. 2) to an image sensor located external to dentalcamera 10.

FIG. 4 shows a cross sectional phantom view of the structure shown inFIG. 3, with elements numbered in a similar fashion. Thus, shown in FIG.5 are fiber optic light guide 30, fiber optic curvature 31, andillumination lens 32. In one embodiment, illumination lens 32 is adispersion lens which serves to properly distribute the light over awider angle and area upon exit from fiber optic light guide 30, tocorrespond to the field of view of image lens 33. FIG. 5 also showsimage lens 33 located within camera head 14 between camera head face 15and image sensor 35. In the embodiment shown In FIG. 5, image lens 33 isaffixed directly to image sensor 35. In an alternative embodiment ofthis invention, image lens 33 is affixed to the body of camera head 14,and image sensor 35 is also affixed, via substrate 36, to the body ofcamera head 14, thereby maintaining image lens 33 and image device 35 infixed relationship. In another embodiment of this invention, fiber opticcurvature 31 is not used, but is replaced by a prism or mirror assemblywhich serves to reflect light from fiber optic light guide 30 to face 15of camera head 14. If desired, a suitable lens can be placed on thefiber optic side of the prism or mirror, or on the face 15 side of theprism or mirror, or in both locations if desired.

In one embodiment of this invention an infrared filter is place betweenthe light source (not shown) and fiber optic light guide 30. Thisinfrared filter serves to prevent damage to fiber optic light guide 30by masking out damaging infrared rays from the light source. In anotherembodiment of this invention, color filters are used as desired. Forexample, color filters can be placed anywhere between the light sourceand illumination lens 32 in order to selectively apply desired colors ofillumination to the image being viewed. Alternatively, one or more colorfilters can be placed between image lens 33 and image sensor 35, againin order to selectively remove desired colors of the image beingpresented to image sensor 35. In yet another embodiment, an infraredblocking filter is placed in the image path between the image beingviewed and image sensor 35 in order to prevent infrared energy frombeing applied to image sensor 35. This is particularly useful, forexample, when a dentist is using a laser to perform certain dentalprocedures during which time a relatively larger amount of infraredenergy is present. If not blocked out this infrared energy would bedetected by image sensor 35 resulting in a "washed out" video signal.

In one embodiment of this invention, forward extension 13 includes fluidjet 39 (FIG. 4) which serves to allow fluid to be introduce across face15 of camera head 14. In this manner, for example, a constant or pulsedflow of gas, such as air, can be made to provide a laminar flow acrossimage lens 33 to prevent fogging. If desired, a liquid such as water canbe introduced as well in order to clean image lens 33. Fluid jet 39 canalso be placed in any convenient location.

FIG. 5 is a block diagram of the electronics portion of a dental camerawhich includes image device 60 such as a charge coupled device (CCD),image device driver buffer 61 which serves to control image device 60,video amplifier circuitry 62, and video processor 8 for controllingdriver buffer 61 and processing the video information which is thenpresented to display 6. For best results, driver buffer 61 and videoamplifier 62 are located very close to image device 60 in order tomaintain the necessary drive pulse waveforms and timing relationships,and insure the optimum frequency response of the video image. Ideally,these circuits are fabricated on the same integrated circuit as imagingdevice 60. Alternatively, driver buffer 61 and video amplifier 62 areformed as individual components in a hybrid or printed circuit boardassembly with imaging device 60. However, in certain embodiments of thisinvention, this is not possible due to size limitations of the dentalcamera head 15 (FIG. 1). Also, the heat generated by driver buffer 61and video amplifier 62 can, in certain instances, impair the operationof the imaging device 60, for example by raising the dark current.

In one embodiment of this invention, driver buffer 61 and videoamplifier 62 are located as either individual circuits, a singleintegrated circuit, or a hybrid assembly, located in any convenientlocation within the dental camera. Such convenient locations are handle11 , forward extension 13, or within connecting cable 7 (FIG. 1).

FIG. 6 is a drawing of one embodiment of a dental camera constructed inaccordance with the teachings of this invention. As shown in FIG. 6,circuitry 101 may be included within handle 11. Circuitry 101 caninclude one or both driver buffer 61 and video amplifier 62 (FIG. 5),and can be formed either as an integrated circuit, hybrid device, orcomponents located on a printed circuit board or the like. If desired,circuitry 101 includes an imaging device which receives visible lightvia, for example, a rod lense assembly or one or more optical, fibers(not shown) which serve to transport the image from dental camera head14 to circuitry 101.

In an alternative embodiment of this invention, electronics as describedabove may be located within cable 201, connector assembly 203, cable204, connector 205, or within processing unit 8 (FIG. 5). Alternatively,various portions of the electronics can be conveniently located within aplurality of locations shown in FIG. 6.

FIG. 7 is a diagram of a dental camera constructed in accordance withthe teachings of this invention which includes provisions in head 14 formounting an external device. In one embodiment of this invention, adental camera is provided which allows for such external devices to beremoved and interchanged, thereby allowing a single dental camera toserve a wide of number of uses.

In accordance with the teachings of this invention, a number of possibleexternal devices are provided, included but not limited to a wide anglelens as shown in FIG. 7, a telephoto lens as shown in FIG. 7a, a rodlens or one or more fiber optic cables serving as a "relay lens" asshown in FIG. 7b. Such a telephoto lens of FIG. 7a is very convenientfor viewing very small areas, for example for use in viewing thecapillaries within the gums, thereby allowing the dentist or oralsurgeon to determine the relative health of the gums by determining thecondition of blood circulation within the gums. Such a telephoto lens isalso useful for obtaining a frontal view of the entire mouth, by holdingthe telephoto lens at an appropriate distance from the patient's face.Use of a telephoto lens for this purpose avoids the frontal image of thepatient's mouth appearing as a "fish eye" view. A relay lens as in FIGS.7b and 7c is highly suitable for viewing the small spaces between theteeth more readily than can be viewed using the dental camera itself.Each of these examples in FIGS. 7, 7a, and 7b include provisions forproviding light to the area to be imaged. These take the form ofadditional lenses or windows 102 which optimize the area and uniformityof illumination to correspond to the angle of view of the lens beingused. Alternatively, a relay lens as shown in FIG. 7c is provided, inwhich, for example, an optical fiber is used to both transmit light tothe area to be imaged, and transmit the image to the dental cameraimaging device contained within dental camera head 14. Filterattachments and lens/filter combinations can also be used. For example,infrared filters can be used to block infrared energy emitted by a laserduring surgery, thereby allowing proper viewing of the surgery inprocess. Alternatively, color filters can be placed in the path of thelight being emitted by the light source in order to selectively applydesired colors of illumination to the image being viewed. Alternatively,filters can be placed in the path of the light being received by theimage device in order to selectively remove desired colors of the imagebeing present to the image sensor.

FIGS. 8, 8a, and 8b show alternative embodiments of the wide angle,telephoto, and relay lenses, respectively, which are capable of beingclapped on to dental camera head 14 which includes slots 105 forreception of attachment bracket 106. Filters can also be used asdescribed above with regard to FIG. 7.

FIGS. 9a through 9d depict various embodiments of a dental cameraconstructed in accordance with the teachings of this invention suitablefor transillumination of an area to be examined. For example, in theembodiments of FIG. 9a and FIG. 9c, illumination means 30, such as anoptical fiber, receives light from a light source within camera head 14(or via means which carries light to camera head 14), and provides thislight via, for example, optical fibers or a rod lens, to the oppositeside of the area being examined, for example a tooth, thereby allowingthe tooth to be transilluminated and the image provided to the dentalcamera head being that of the transilluminated tooth. Alternatively,this transillumination technique will allow the exterior of the tooth tobe illuminated, and the interior of the tooth to be viewed, for exampleto view a cavity within the tooth, or the root canal. In one embodimentof this invention, illumination means 30 are malleable in order to allowtheir position with respect to camera head 14 to be altered, as desired.

As shown in the embodiments of FIGS. 9b and 9d, light is emanated fromcamera head 14 for transillumination of an area to be viewed, and thetransilluminated image is received by means 38, such as one or moreoptical fibers, or a rod lens, for transmission to the imaging devicewithin the dental camera. In one embodiment of this invention, means 38is malleable to allow its position relative to camera head 14 to bealtered; as desired.

In an alternative embodiment of this invention, as shown in FIG. 9e, aseparate transillumination light source 130 is used, which is attachedto camera body 16 by attachment means 131. If desired, attachment means131 can allow the position of transillumination light source 130 to bechanged relative to camera head 14. In this embodiment, camera head 14either does not include light sources, or the light sources containedwithin camera head 14 are turned off during the use of transilluminationlight source 130.

FIG. 9f depicts an alternative embodiment of a transillumination deviceconstructed in accordance with the teachings of this invention. As shownin FIG. 9f, camera head 14 includes a central cavity 220 which is placedin order to house the object to be transilluminated. On the interiorwalls of transillumination head 14 is included optical ports 230 and231, either one of which may be the source of transillumination light,with the opposite optical port serving as the port for receiving thetransilluminated image.

In another embodiment of this invention (FIG. 10), a rod lens or one ormore optical fibers 91 are used for attaching the dental camera directlyto a dentist's drill 92, thereby allowing the operation being performedby the dentist using his drill to be viewed on a video monitor. In analternative embodiment shown in FIG. 11, a dental camera 10 is mountedto a dental drill 92, for example, by means of one or more clips or ties98. In yet another embodiment of this invention, as shown in FIG. 12,the dental camera and dental drill are combined in a single instrumentincluding camera head 14a attached to the end of dental drill/camera92a. In one embodiment of this invention, camera head 14a includes animaging device. In an alternative embodiment of this invention, camerahead 14a includes means for receiving image, such as a fiber optic or arod lens assembly, for transmission to an imaging device located withindrill/camera 92a, or to the cable (not shown) or processor (not shown)attached to drill/camera 92a.

All publications and patent applications are herein incorporated byreference to the same extent as if each individual publication or patentapplication was specifically and individually indicated to beincorporated by reference. The invention now being fully described, itwill be apparent to one of ordinary skill in the art that many changesand modifications can be made thereto without departing from the spiritor scope of the appended claims.

What is claimed is:
 1. A method for obtaining a video image of alocation within the mouth of a patient comprising the stepsof:manipulating a dental instrument having an optical informationreceiving face shaped to be positioned within said mouth, to pick upoptical information from said location defining an image of the same;delivering illumination with said instrument to said location while saidoptical information is picked up; providing a source of illuminationexterior to said instrument; directing illumination from said source tosaid instrument; electrically connecting a video monitor to saidinstrument for visually displaying said image; and positioning a filterrelative to said face to remove selected wavelengths fromelectromagnetic radiation presented to said face of said instrument. 2.The method of claim 1 wherein said dental instrument includes a handlefor gripping by a user and an extension shaped to fit within said mouthhaving said optical information receiving face, and wherein said step ofmanipulating said dental instrument includes manipulating the same toview the distal, labial, buccal, and lingual aspects of teeth at saidlocation.